Yamaha V-Star 1100 carburetor experts! Backfiring on low speed decel Idle speed changes as bike warms Cobras?

I just purchased an 03 1100 w/ 10,000 miles. It has Cobra pipes w/o baffles. kjc intake. The carb was supposed to have been rejetted but cannot confirm w/o removal. Bike is getting good mileage and runs fine at hwy speeds but backfires a lot at lower speeds. The idle speed varies from warm to cold. Suggestions? Good carb mechanic in So Cal?